Angry nationalists have lashed out at Scotland’s largest supermarket chains
after two warned they may be forced to increase food prices after
independence.

A member of the official Yes Scotland campaign's team of executive directors said it would be “great” if Tesco, Morrisons, Sainsbury’s and Asda pulled out of the country following victory in next year’s referendum.

Other nationalists, including an SNP councillor, called for a boycott in retaliation against the comments by the chief executives of Asda and Morrisons.

In interviews with the Financial Times, the pair said they would be unwilling to absorb the extra costs of doing business in a separate Scotland or to pass on any additional costs to customers elsewhere in the UK.

The argued they already have lower margins north of the Border due to higher distribution costs and a Scottish Government tax on large shops that sell both tobacco and alcohol.

The comments were welcomed by Better Together, the campaign to keep Scotland part of the UK, while a senior academic advised voters to consider their “food security” when casting their votes in the referendum.

But nationalists were fuming at the intervention, one of the few made so far in the independence debate by big business amid accusations of intimidation tactics by SNP ministers.

Robert Peston, the BBC’s business editor, yesterday reported how the boss of one of the UK’s largest companies held a meeting with the Scottish Government that became “very dark” and “very aggressive” after they criticised independence.

Stan Blackley, Yes Scotland’s deputy director of communities, took to the social networking site Twitter to attack all four of the largest supermarket chains following the warnings by Asda and Morrisons.

“Wouldn’t it be great if Tesco, Sainsbury’s, Morrisons (and) Asda just left Scotland after Yes vote,” he tweeted, adding that this was his personal view.

David Turner, an SNP councillor from Glasgow, tweeted: “Now it looks as though two of the major supermarkets are part of the Better Together campaign. Time to boycott.”

Although Coalition ministers have said household bills may increase after independence – the UK has the only EU opt-out allowing zero per cent VAT on food – it is the first time the major supermarkets have echoed this warning.

Dalton Philips, chief executive of Bradford-based Morrisons, told the Financial Times: "If the regulatory environment was to increase the burden of the cost structure on business, that would potentially have to be passed on to consumer pricing.

“Why should the English and Welsh consumer subsidise this increased cost of doing business in Scotland?”

Andy Clarke, chief executive of Asda, said his firm believes in “fairness” and charges customers the same for a pint of milk or loaf of bread regardless of where they live in the UK.

"However, the cost of doing business in different parts of the UK does vary and the powers given to the Scottish Parliament in the 2012 Scotland Act and any yes vote in 2014 could result in Scotland being a less attractive investment proposition for businesses and put further pressure on our costs,” he added.

A senior executive from one of the major supermarkets was quoted anonymously as saying: "We would treat it as an international market and act accordingly by putting up our prices.

“The costs of distribution are much higher in Scotland but at the moment that gets absorbed by the UK business."

Supermarkets also have to pay the Scottish Government a “health levy” of £30 million a year to sell tobacco and alcohol and Scots consume more branded products, which have lower profit margins.

Tim Lang, professor of food policy at City University, told the Huffington Post: "Food prices are rising already. Scotland hasn't got the most benign of climates to do business.

“The supermarkets here are rattling their cages. Scots would be well advised to start thinking about their own food security.”

John Lamont, the Scottish Tory Chief Whip, said: “Perhaps the excitable and occasionally venomous reaction from ‘cyber-nats’ – not least Mr Blackley – explains why more businesses don't air their views on separation.”

Margaret Curran, Labour’s Shadow Scottish Secretary, said: “The message from supermarket bosses is clear – the cost of doing the weekly shop in Scotland is cheaper as part of the UK and would be more expensive with independence.”

Sainsbury's declined to comment, while a Tesco spokesman said: "We've got a great business in Scotland and our job is to create the best offer for customers whatever the outcome of the referendum.”

Richard Lochhead, the Scottish Rural Affairs Minister, highlighted this comment and the fact Asda and Morrisons have no firm plans to increase prices as evidence the warnings had “quickly disintegrated”.

He said: “Supermarkets operate in competition with each other, and you can be sure if one supermarket chain has higher prices – for whatever reason – then their competitors will not be slow to take advantage of that.”